Discharge apparatus and method



June 26, 1934. R. E. BARCLAY DISCHARGE APPARATUS AND METHOD Filed June l. 1931 Patented June 26, 1934y Discman APPARATUS Aun Mn'rirol y Chicago, Ill., assignor tov I Federal Electric Company, poration o! New York Robert E. Barclay,

Chicago, Ill., a cor- Application June 1, 1931, serial 1-10.'541,:f.'en

v1s claims. (01.;1'16-124) My invention relates in general to electronics, and has more particular reference to electronic discharge apparatus, the invention more specifically relating to a discharge illuminating device and means to operate same from a low voltage source of electrical power.

Among, the important objects of the present invention is to provide a device of the class described having novel structural features cooperatingto permit an electronic discharge to be initiated under the influence of-a relatively low electrical potential, as distinguished from the relatively high voltage necessary to start or initiate discharge in devices of the 'same type heretofore provided.

Another important object of the invention is to provide an alternating current hot cathode vacuum tube.

Still another object is to provide a luminescent element of the class described operable from a power sourcehaving voltage of the order found in the ordinary commercial or house lighting cir` cuit. Another important object is to provide in a device of the class described means operable when power is initially applied to the element, for conditionlng the device so that the discharge may be initiated or started at a voltage of a magnitude otherwise and ordinarily incapable o! starting the discharge, and the invention includes additionally the means for rendering said means inactive after the arc has been set up,

whereby the illuminating device may be started and maintained in operation solely by an impressed voltage of a magnitude ordinarily insufcient to initiate the discharge.

The invention also includes the switching means for actuating the exciting or discharge producing system, and for changing connections to render the exciting system inoperative after the discharge has been started.

The invention also contemplates and embraces the particular structure of the. enclosing envelope dividing the discharge arc path in combination with the other features of novelty.. The particular structure of the envelope per se is, however, not claimed in the present application, since the same forms the subject matter of a co-pending application, Serial Number 541,390, led the ilrst day of June, 1931.

Numerous other objects and advantages of the invention will be clearly apparent as the invention is more fully understood from the following description, which, taken with the accompanying drawing, discloses a preferred form or embodiment of the invention.

Referring to the drawing:

Figure 1 is a vertical 'section'taken through a device embodying my'present invention, the wir- 60 -fing at the lower ,end of the device being shown diagrammatically;

Figure 2 is a similar vertical section taken through the lower portions of the apparatus indicated in Figure 1- to show an actual preferred 65 construction and assembly;

Figure 3 is a section taken substantially along the line 3-3 in Figure 2;

Figure 4 is a fragmentary section taken through the lower portions of the device illustrated in Figure 1 to' show a modied electrode construction; and

Figure 5 is a section taken substantially along the line 5-5 in Figure 1 toillustrate the .structure of the envelope.l A

To illustrate my invention, I have shown lonl the drawing an electric discharge device 11 comprising 'an envelope 13 and a supporting base 15. 'I'he envelope 13 is formed preferably of any suitable light-transmitting material such as glass, and is arranged to provide a closed chamber or channel 15 which,l in the' illustrated embodiment, issubstantially in the form of an inverted U,. the arms of the U being disposed in parallel and adjacent relationship and being separated by a partition 17 which extends within the enclosing walls 19 of the envelope 13. This particular envelope construction has certain features of advantage which are hereinafter more fully described. However, my present invention is not necessarily limited by the particular construction of the envelope, but may b'e applied ln devices having discharge channels arranged in any desired or suitable form or conguration. I prefer, however, to have the opposite ends of the channel 95 15 disposed somewhat adjacently, so that the lower end of the envelope including the opposite ends of -the channel 15 maybe mounted in and -supported from the base 15, which is provided with terminal means 21 whereby the device may 100 be connected with a suitable source of electrical power, such, for instance, as the outlet of an ordinary house wiring system.

At the opposite ends of the'channel 15 are mounted electrodes 23 and 25 between which a 1N discharge may be sustained. Means is also provided for applying a suitable potential difference between the electrodes, whereby to sustain the discharge through the channel 15. The channel 15 is evacuated, purified, and lled with any suit- 110 able discharge sustaining gaseous medium, such as neon, argon, crypton, mercury vapor, or any other gas capable of providing an ionized path for an electron ilow or discharge between the electrodes.

Ordinarily relatively high potential difference would have to be applied between the electrodes in order to set up an electronic discharge through the evacuated gas-filled channel 15 between the electrodes. In order to provide for the initiation or setting-up of a discharge at low voltage, I introduce and arrange in the channel 15 an additional electrode 27, which I prefer to call the exciting electrode. This electrode is preferably arranged in closely spaced' relationship with respect to the electrode 23, so that when low voltage power is applied between the exciting electrode 27 and the electrode 23, a discharge will pass between these two electrodes. Ordinarily voltages of the order lof 110 volts, such as are found in the ordinary commercial or house-lighting circuit, will readily create an`electrical discharge arc when impressed on electrodes 23 and 27, closely spaced as indicated. As soon as the discharge occurs between the electrode 23 and the exciting electrode 27, heat will be generated which will penetrate the arm of the channel 15 in which the electrode 23 and the exciting electrode are located. 'I'he heat generated in this arm will ionize the gaseous material in the channel to an extent which will permit an arc to be set up between the electrodes 23 and 25, operating respectively as cathode and anode, through the channel 15 at a relatively low voltage impressed between the anode and the cathode.

Any suitable connection or connections may be provided for impressing the energizing voltage between the electrode. 23` and the exciting electrode 27, and between the electrodes 23 and 25. However, I prefer to employ the circuit or system illustrated, and which includes an autotransformer 29 havingA its primary winding 31 connected to a suitable power source and having its secondary winding 32 connected to the several electrodes 23, 25dy and 27r in such a way that a suitable exciting discharge 'may be initially yset up between the electrodes 23 and 27 and a discharge set up and sustained between the anode and theA cathode after the gases in the channel 15 have been partially ionized by the exciting discharge. It is obvious that the voltage necessarily impressed between the electrode 23 and the exciting electrode 27 may be considerably less than .the exciting and sustaining voltage impressed between the electrodes 23 and 25, and the connections may be completed accordingly. As illustrated, power is applied between the electrodes 23 tire secondary winding of the auto-transformer.

After the discharge has been initiated between the electrodes 23 and 25, it is no longer necessary to sustain the exciting or ionizing discharge and the exciting electrode, and for this reason I have provided means comprising a relay 33 which operates normally to complete the exciting circuit, but which, as soon as the discharge starts between the electrodes 23 and 25, operates to` break the connection between the auto-transformer and the exciting electrode 27. The relay 33 may be of any desired or convenient construction, but I prefer to employ a magnetiic relay comprising a coil 35 connected in series between the electrode 25 and the secondary of the 4is pivoted to swing adjacent the` end of the coil 35. 'I'he armature carries acontact 39 adapted to cooperate with a stationary contact 41 mounted on a bracket 43 in the path of movement of the armature. The armature is normally pressed by means of a spring 45 or other convenient means so ,that contact 39 engages the contact 41. The armature 37 and the bracket 43 are connected, one to the exciting electrode 27 and the other to the secondary of the auto-transformer, so that when the` coil 35 is not excited, the spring 45 closes the contacts 39 and 41 and completes a circuit between the transformer secondary and the exciting electrode. Consequently whenthe power is turned on to energize the illuminating device 11, `a potential diierence will be immediately applied between the electrodes 23 and 25, but, the path 15 being as yet un-ionized, and the potential difference between the electrodes 23 and 25 being insuiicient to bridge the un-ionized gap, an electric discharge will not be set up through the channel l5. A potential difference, however, will also be impressed between the electrode 23 and the electrode 27 which, on account of the close proximity of the electrodes, will establish a discharge therebetween. This discharge will quickly heat the electrodes 23 and 27, and will result in the rapid ionization of the gas-filled channel 15. When the contents of the channel are sufficiently ionized to permit vthe voltage impressed between the electrodes 23 and 25 to initiate a discharge through the' channel, current will flow in the connection between the electrode 25 and the transformer through the coil 35 of the relay. This will attract the armature 37 and will separate the contacts 41 and 39 and thus sever the exciting circuit and the ionizing discharge between the electrode 23 and the exciting electrode 27 will be quenched, but the main discharge between the electrodes 23 and 25 through the channel 15 will besusta'ined by the relatively. low voltage impressed between the electrodes 23 and 25. It is possible in this way to sustain the discharge at relatively low voltages of the order usually supplied in commercial or house-lighting circuits, and a device embodying the foregoing construction inay be successfully operatedwith an impressed voltage of approximately 110 volts between the electrodes 23 and 25, the auto-transformer 29 being merely to facilitate the supply of a suitable reduced voltage between theelectrode 23 and the exciting electrode 27. If desired, the auto-transformer may be replaced by a relatively high protective resistance, the exciting electrode connection being tapped oif from this resistance ata suitable point therein to provide a desired voltage between the electrode 23 and the exciting electrode with a standard voltage impressed across the end-s of the resistance.

I prefer also to arrange the relay 33 and the auto-transformer 29 or its equivalent resistance in the base 15, which preferably comprises a cup-shaped shell 47, in which the electrodes 21 may be arranged in any convenient or suitable manner. The shell 47 may be formed of insulating material as illustrated and the terminals 21 may be of the nger type, adapted to cooperate in corresponding sockets of a circuit outlet, or the shell 47 may be formed as a metallic shell provided with a screw-threaded formation, in which case the shell itself forms one of the electrodes 21, the other electrode comprising a centrally disposed stud. This `latter basal construction .is common andv well known in the art, and is universally employed in -theconstruction of incandescent lamps. The transformer 29 or its equivalent resistance is preferably ldisposed inl the shell, being connected between the electrodes 2l. Above the transformer in thev shell 27 I prefer to arrange the relay 33, the several parts of which are or maybe {Supported on a suitable base comprising adisk491se`cured'iirany convenient manner in the shell 47'. v" I'lie relay mechanism isin Vturn'covered with a plate51', and thel space above the plate is iilled with a Vsuitable insulating compound 5'3 in which the ends ofthe this instance comprises 'a envelope 13 are imbedded. It is desirable to thus separate the insulating compound from the relay mechanism, since a certain amount of movement is necessary in the operation of the relay, which would otherwise be impeded if'the same were imbedded in the insulating compound. The

transformer 29 or its equivalent resistance', being a stationary device, however, may also be imbedded in an insulating compound as indicated In Figure 4 of the drawing I have illustrated a modiedv electrode construction wherein the electrodes 23 and 25 comprise a cylindrical block of any suitable material, such as copper, copper alloy, tungsten, or an`y of the rare metals such as may be employed for the purpose, the same being supported in the ends of the channel 15 on wires 57 of suitable conducting material leading out through the envelope, and by which discharge sustaining voltages may be impressed upon the electrodes. The exciting electrode in filament 59 in the form of a coil of wire, extending through the central bore of the cylindrical electrode 23, and extendingr thence out through thelower sealed end of the envelope. In this form of the device, when the exciting voltage is impressed between the elect-rode lead and the filament lead, the filament 59 will be itself heated, and in turn heat the electrode 23, and the generated heat will ,result in the ionization of the gases filling the discharge channel l5. Otherwise the operation of devices containing the modifications shown in Figure 4 is the same as heretofore described in connection with the embodiment illustrated in Figures 1 and 2.

It is thought that the invention and numerous of its attendant advantages will be fully understood from the foregoing description, and it is obvious that numerous changes may be made in the form, construction and arrangement of the several parts without departing from the spirit or scope of the invention' or sacrificing any o! its attendant advantages, the form hereinbefore described being a preferred embodiment for the purpose of illustratin the invention. v

Having thus descri ed my invention, what I claim as new and desire to secure by Letters Patent is:

1.l A discharge device comprising an envelope forming a discharge channel, actuating electrodes arranged in spaced relationship in said channel, said envelope having an integral portion extending between said electrodes; means to apply a discharge sustaining electrical potential diii ence between said electrodes, exciting means ope' able upon the applicationof discharge sustaining potential diierence between the electrodes and operable to excite the discharge path therebetween to e nein-eeA benutting the, cischarge sustaining potential difference to initiatef" an electrical discharge between the velectrodesthrough vthe intermediate channel, and discharge controlled means operable upon the initiation of such discharge to disconnect said exciting means from operation.

2. In' a device of the. class described, means forming an envelope defining substantially parallel and adjacent electrical dischargel path portions, said v portions being s enaratecl-bye19,-; m'ngf mon wall or partition 'formed' infth'e'- envelope and portions, whereby to provide for the initiation of an electronic discharge in said channel portions between the electrodes without increasing the voltage impressed upon the electrodes, and' 100 means to discontinue operation of the exciting means upon the initiation of the'electron discharge.

3. In a discharge device' comprising an envelope, said envelope comprising a substantially cylindrical tubefsealed at its opposite ends, an integrall partition extending from one sealed end to adjacent the other sealed end to provide within the tube a substantially U-shaped discharge channel, the arms of which are separated by said partition, a pair of spaced-apart electrodeslocated one in each arm of the'channel on opposite sides of the partition, a gaseous medium within said channel and adapted to glow when excited by electrical discharges therethrough, means vto apply an electrical potential 'difference between said main electrodes suillcient to sustain a discharge between the electrodes but of insufficient magnitude to initiate the discharge, an exciting element in said channel and associated with one of said electrodes, and means forming an exciting circuit connected with the exciting element to energize same in order to excite the medium within the channel sufliciently to permit the discharge sustaining potential to initiate a discharge within the channel between the electrodes.

4. A discharge device comprising an envelope forming a discharge channel, actuating electrodes arranged in spaced relationship in said channel, said envelope having an integral portion extending between said electrodes, means to apply electrical potential difference between said electrodes, exciting means operable upon the ap.. plication of .potential diierence between said electrodes to excite the discharge path therebetween to a degree permitting the applied potential diiierence to initiate an electrical discharge between the electrodes through the intermediate channel, which the excitingmeans comprising an exciting electrode in the discharge channel and mounted in closely spaced relationship with respect to one of the actuating electrodes.

5. A discharge device comprising an envelope forming a discharge channel, actuating electrodes arranged in spaced relationship in said channel, said envelope having an integral portion extending between said electrodes, means to apply electrical potential difference between said electrodes, exciting means operable upon the application of potential difference between s aid channel, the exciting means comprising an exciting electrode in the discharge channel and mounted in closely spaced relationship with respect to one of the actuating electrodes, and means to apply a potential diierence between the closely spaced exciting and actuating electrodes suicient to initiate an electrical discharge Ithere- 6. Avdischarge device comprising an envelope forming a discharge channel, actuating electrodes arranged in spaced relationship in said channel, said envelope having anfintegral portion extending between said electrodes, means to apply electrical potential difference between said electrodes, exciting means operable upon the application of potential difference between said electrodes to excite the discharge'path therebetween to a degree permitting the applied potential difference to initiate anvelectrical discharge between the electrodes through the intermediate channel, the exciting means comprising a lilament in the discharge channel.

7. A discharge device comprising an envelope forming a discharge channel, actuating electrodes arranged in spaced relationship in said channel, said envelope having an integral portion extending between said electrodes, means to apply electrical potential difference between said electrodes, exciting means operable upon the application of potential difference between said electrodes to excite the discharge path therebetween to a degree permitting the applied potential difference to initiate an electrical discharge be- .tween the electrodes through the intermediate channel, at least one of the actuating electrodes apply electrical potential difference between said electrodes, exciting means operable upon the application of potential difference between said electrodes to excite the discharge path therebe- -tween to a degree permitting the applied potential difference to initiate an electrical discharge between the electrodes through the intermediate channel, the exciting means comprising a heat generating filament in the discharge channel, and means to deliver an electrical current to the filament to energize the same.

9. A discharge device comprising an envelope forming a discharge channel, actuating electrodes arranged in spaced relationship in said channel, said envelope having an integral portion extending between said electrodes, means to apply electrical potential difference between said electrodes, exciting means operable upon the application of pc-tential dilerence between said electrodes to excite the discharge path therebetween to a degree permitting the applied potenial 'difference to initiate an electrical discharge between the electrodes through the intermediate channel, an energizing circuit for the exciting means comprising a conductor including switch means operatively associated with the discharge controlled means.

10. A discharge device comprising an envelope forming a discharge channel, actuating electrodes arranged in spaced relationship said channel, said envelope having an integral portion extending between said electrodes, means to apply electrical potential difference between said electrodes, exciting means operable upon the application of potential difference between said electrodes to excite the discharge path therebetween to a degree permitting the applied potential dilerence to initiate an electrical discharge between-the electrodes through the intermediate channel, the discharge controlled means comprises a relay including a normally closed switch connected in circuit with the exciting means, said relay being operable upon the initiation of a discharge between the actuating electrodes to open said switch.

11. A discharge device comprising an envelope forming a discharge channel, actuating electrodes arranged in spaced relationship in said channel, said envelope having anvintegral portion extending between said electrodes, means to apply electrical potential difference between said electrodes, exciting means operable upon the application of potential difference between said electrodes to excite the discharge path therebetween to a degree permitting the applied potenial difference to initiate an electrical discharge between the electrodes through the intermediate channel, the means for applying the dischargesustaining potential difference between the electrodes comprising a transformer, and a secondary connected between the electrodes and having a tap connection with the exciting means.

l2. A discharge device comprising an envelopeforming a discharge channel, actuating electrodes arranged in spaced relationship in said channel, said envelope having an integralportion extending between said electrodes, means to apply electrical potential difference between said electrodes, exciting means operable upon theA application of potential diierence between said electrodes to excite the discharge path therebetween to a degree permitting the applied potential difference to initiate an electrical discharge between the electrodes through the intermediate channel, the means for applying the discharge sustaining potential difference between theelectrodes comprising a transformer, and a secondary connected between the electrodes and -having a tap' connection with the exciting means, the discharge controlled means being co-operatively associated with said tap connection.

13. .A device as set forth in claim l, wherein the electrodes are mounted in the opposed ends oi the discharge channel, said ends being disposed in closely abutting relationship and a shell receiving said ends and supporting said casing, said shell forming a housing for said discharge controlled means and the potential applying means, and being formedto t a power outlet socket, and means on the shell for electrically connecting said potential applying means in the outlet socket.

14. A device as set :forth in claim l wherein the electrodes are mounted in the o-pposed ends of the discharge channel, said ends being disposed in closely abutting relationship and wherein the means for applying the discharge sustaining potential diierence between the electrodes comprises a transformer, a secondary connected between the electrodes and having a tap connection with the exciting means, said transformer having a primary, a shell forming a mounting for said casing and receiving the ends of said arms and said envelopeforming. a-partition therebetween,

an electrode in each arm of Athechannel, and

means 'associatedwith at least one of said electrodes for the purpose of Awarming thesame Vto promote electron emissicn.-

16. A discharge devicecomprsing an integral envelope providingv a U-shaped discharge chanby an integral part nel having' arms f separated of said envelope forming a` partition Vtherebetween, an electrode in each larm of the channel,

at least one of said electrodes comprising a laloA 1'?.A A discharge device comprising'an integral envelope providing a U-shaped discharge channel having arms lseparated by an integral part of said .l envelope forming a partition therebe- 4 v 5l '.ment capable of being heated to promote the remissionof electrons therefrom.

tween, an electrode in each' arm of the channel,`

at least one of said 'electrodes comprisinga. hollow shell adapted to be heated for. electron emission and a filament within thepvshell for heating the's'ame.

18. A dischargedevice`- comprising an integral Y envelope providing a U-shaped discharge channel having arms separated by anintegral part of Vsaid envelope forming a partition therebetween. lan electrode in each arm of the channel, and another electrode atleast one of said arms.

ROBERT E. BARCLAY. 

